diff --git a/app/src/main/java/xdsopl/robot36/Decoder.java b/app/src/main/java/xdsopl/robot36/Decoder.java
index 9d86bfd..2636d45 100644
--- a/app/src/main/java/xdsopl/robot36/Decoder.java
+++ b/app/src/main/java/xdsopl/robot36/Decoder.java
@@ -160,8 +160,7 @@ public class Decoder {
 
     void clear_image() { rsDecoder.invoke_reset_buffer(); }
     void toggle_scaling() { image.intScale ^= true; }
-    void softer_image() { rsDecoder.invoke_incr_blur(); }
-    void sharper_image() { rsDecoder.invoke_decr_blur(); }
+    void adjust_blur(int blur) { rsDecoder.invoke_adjust_blur(blur); }
     void toggle_debug() { rsDecoder.invoke_toggle_debug(); }
     void toggle_auto() { rsDecoder.invoke_toggle_auto(); }
     void enable_analyzer(boolean enable) { rsDecoder.invoke_enable_analyzer((enableAnalyzer = enable) ? 1 : 0); }
diff --git a/app/src/main/java/xdsopl/robot36/MainActivity.java b/app/src/main/java/xdsopl/robot36/MainActivity.java
index 2bafc67..9767b7a 100644
--- a/app/src/main/java/xdsopl/robot36/MainActivity.java
+++ b/app/src/main/java/xdsopl/robot36/MainActivity.java
@@ -227,11 +227,26 @@ public class MainActivity extends Activity {
             case R.id.action_clear_image:
                 decoder.clear_image();
                 return true;
-            case R.id.action_softer_image:
-                decoder.softer_image();
+            case R.id.action_sharpest_image:
+                decoder.adjust_blur(-3);
                 return true;
             case R.id.action_sharper_image:
-                decoder.sharper_image();
+                decoder.adjust_blur(-2);
+                return true;
+            case R.id.action_sharp_image:
+                decoder.adjust_blur(-1);
+                return true;
+            case R.id.action_neutral_image:
+                decoder.adjust_blur(0);
+                return true;
+            case R.id.action_soft_image:
+                decoder.adjust_blur(1);
+                return true;
+            case R.id.action_softer_image:
+                decoder.adjust_blur(2);
+                return true;
+            case R.id.action_softest_image:
+                decoder.adjust_blur(3);
                 return true;
             case R.id.action_toggle_scaling:
                 decoder.toggle_scaling();
diff --git a/app/src/main/res/menu/menu_main.xml b/app/src/main/res/menu/menu_main.xml
index 8d8ff88..68d8259 100644
--- a/app/src/main/res/menu/menu_main.xml
+++ b/app/src/main/res/menu/menu_main.xml
@@ -27,8 +27,15 @@
             android:icon="@android:drawable/ic_menu_close_clear_cancel"
             android:showAsAction="ifRoom" />
 
-        <item android:id="@+id/action_softer_image" android:title="@string/action_softer_image" />
-        <item android:id="@+id/action_sharper_image" android:title="@string/action_sharper_image" />
+        <item android:title="@string/image_sharpness"><menu>
+            <item android:id="@+id/action_sharpest_image" android:title="@string/action_sharpest_image" />
+            <item android:id="@+id/action_sharper_image" android:title="@string/action_sharper_image" />
+            <item android:id="@+id/action_sharp_image" android:title="@string/action_sharp_image" />
+            <item android:id="@+id/action_neutral_image" android:title="@string/action_neutral_image" />
+            <item android:id="@+id/action_soft_image" android:title="@string/action_soft_image" />
+            <item android:id="@+id/action_softer_image" android:title="@string/action_softer_image" />
+            <item android:id="@+id/action_softest_image" android:title="@string/action_softest_image" />
+        </menu></item>
 
         <item android:id="@+id/action_toggle_scaling" android:title="@string/action_toggle_scaling" />
         <item android:id="@+id/action_toggle_debug" android:title="@string/action_toggle_debug" />
diff --git a/app/src/main/res/values-de/strings.xml b/app/src/main/res/values-de/strings.xml
index baf8b6e..abe5c41 100644
--- a/app/src/main/res/values-de/strings.xml
+++ b/app/src/main/res/values-de/strings.xml
@@ -26,8 +26,14 @@
     <string name="action_scottie2_mode">Scottie2 Modus</string>
     <string name="action_scottieDX_mode">ScottieDX Modus</string>
     <string name="action_wraaseSC2_180_mode">WraaseSC2 180 Modus</string>
-    <string name="action_softer_image">Weicheres Bild</string>
-    <string name="action_sharper_image">Schärferes Bild</string>
+    <string name="image_sharpness">Bildschärfe Anpassen</string>
+    <string name="action_sharpest_image">am schärfsten</string>
+    <string name="action_sharper_image">schärfer</string>
+    <string name="action_sharp_image">scharf</string>
+    <string name="action_neutral_image">neutral</string>
+    <string name="action_soft_image">weich</string>
+    <string name="action_softer_image">weicher</string>
+    <string name="action_softest_image">am weichsten</string>
     <string name="action_toggle_scaling">Skalierung umschalten</string>
     <string name="decoder_view">Dekodierer Ansicht</string>
     <string name="spectrum_view">Spektrum Ansicht</string>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 9a6a163..e29b0cf 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -26,8 +26,14 @@
     <string name="action_scottie2_mode">Scottie2 Mode</string>
     <string name="action_scottieDX_mode">ScottieDX Mode</string>
     <string name="action_wraaseSC2_180_mode">WraaseSC2 180 Mode</string>
-    <string name="action_softer_image">Softer Image</string>
-    <string name="action_sharper_image">Sharper Image</string>
+    <string name="image_sharpness">Image Sharpness</string>
+    <string name="action_sharpest_image">sharpest</string>
+    <string name="action_sharper_image">sharper</string>
+    <string name="action_sharp_image">sharp</string>
+    <string name="action_neutral_image">neutral</string>
+    <string name="action_soft_image">soft</string>
+    <string name="action_softer_image">softer</string>
+    <string name="action_softest_image">softest</string>
     <string name="action_toggle_scaling">Toggle Scaling</string>
     <string name="decoder_view">Decoder View</string>
     <string name="spectrum_view">Spectrum View</string>
diff --git a/app/src/main/rs/blur.rsh b/app/src/main/rs/blur.rsh
index 7ebe90e..5c8b282 100644
--- a/app/src/main/rs/blur.rsh
+++ b/app/src/main/rs/blur.rsh
@@ -21,14 +21,9 @@ limitations under the License.
 #include "state.rsh"
 #include "blur_generated.rsh"
 
-void incr_blur()
+void adjust_blur(int blur)
 {
-    user_blur = user_blur < 6 ? user_blur + 1 : user_blur;
-}
-
-void decr_blur()
-{
-    user_blur = user_blur >= 0 ? user_blur - 1 : user_blur;
+    user_blur = clamp(blur, -3, 3);
 }
 
 #endif
diff --git a/app/src/main/rs/blur_generated.rsh b/app/src/main/rs/blur_generated.rsh
index edc3e97..349e920 100644
--- a/app/src/main/rs/blur_generated.rsh
+++ b/app/src/main/rs/blur_generated.rsh
@@ -5,7 +5,7 @@ static uchar value_blur(int pixel, int begin, int end)
 	int i = p & buffer_mask;
 	int weight_sum = 0;
 	int value_sum = 0;
-	switch (blur_power + user_blur) {
+	switch (max(0, blur_power + user_blur)) {
 	case 0:
 		if ((p-1) < begin || end <= (p+1) || (i-1) < 0 || buffer_length <= (i+1)) {
 			if (begin <= (p-1)) {
diff --git a/utils/blur.c b/utils/blur.c
index bdb056a..f91c767 100644
--- a/utils/blur.c
+++ b/utils/blur.c
@@ -63,7 +63,7 @@ int main()
 	printf("\tint i = p & buffer_mask;\n");
 	printf("\tint weight_sum = 0;\n");
 	printf("\tint value_sum = 0;\n");
-	printf("\tswitch (blur_power + user_blur) {\n");
+	printf("\tswitch (max(0, blur_power + user_blur)) {\n");
 	int max_power = 6;
 	for (int i = 0; i <= max_power; ++i) {
 		printf("\tcase %d:\n", i);